Devices can utilize one or more antennas to help establish a type of communication link. Examples of such devices and/or antennas may be appreciated from European Patent Publication Nos. 1 630 898 and 2 355 243, U.S. Pat. Nos. 4,700,197, 5,407,075, 7,450,077, 7,461,444, 7,629,934, 8,208,980, and 8,624,787 as well as U.S. Pat. App. Pub. Nos. 2004/0185924, 2006/0109192, 2011/0260939, 2013/0293441 and 2014/0104136.
Attempts have been made to try and use different types of antennas for wearable applications, such as a 2.4 GHz band antenna that includes a planar monopole/dipole antenna, an inverted-F antenna, a slot antenna, and a slot antenna with artificial magnetic conducting surface backing. But, such antenna designs have deficiencies that prevent them from being feasible options for such systems. For example, the monopole/dipole antennas direct a large amount of energy that is radiated to a human body, which generates an undesirable high specific absorption rate in the tissue of the human body. The inverted-F antenna and slot antenna designs also have most of the energy radiated toward a particular top half space. These antennas' form-factors are still not compact enough for feasible or practical application with wearable medical devices that can be suitable for being worn by humans or other living animals. Additionally, the inverted-F antenna and slot antennas can suffer from low front-to-back ratio and low antenna efficiency.